Earlier on Sunday, Abdul-Wahad Saadi, the Iraqi army commander heading the counter-terrorism operation in the city, said that Iraq's armed forces had "fully liberated" Fallujah.
Abadi, who is also the commander in chief of the armed forces, raised the Iraqi flag next to the city hospital while surrounded by dozens of security personnel, the Alsumaria television channel reported.
The prime minister called on Iraqi people to celebrate the victory and vowed to raise the country's flag in Mosul, which is still overrun by Daesh militants.
The Iraqi Army and Shiite militias, backed by US airstrikes, launched the offensive to retake Fallujah on May 22.
Last week, Iraqi Prime Minister Haider Abadi declared Fallujah liberated from the Daesh, as the government forces gained control of the city center. However, media reported that fighting continued in the city. The United Nations earlier voiced concern over the humanitarian situation in the city, with tens of thousands of residents having fled the fighting.